scholarly journals Anti-Helicobacter pylori vaccine: mith or reality?

2019 ◽  
Vol 9 (3-4) ◽  
pp. 457-466
Author(s):  
Yu. P. Uspenskiy ◽  
N. V. Baryshnikova ◽  
E. I. Ermolenko ◽  
A. N. Suvorov ◽  
A. V. Svarval

Here we review the data on the current studies aimed at developing anti-Helicobacter pylori vaccines. Unfortunately, no vaccines recommended for use in human are available now, despite a more than 30-year history of their development and a great body of evidence on vaccine efficiency in animals. Mechanisms underlying vaccine-related effects in animals and human are poorly determined and expect to be further clarified. Moreover, side effects related to vaccines have not investigated in detail. A long-lasting stay of H. pylori in the gastric lumen restricts potential protective effects of host cellular immunity (an effect is mainly associated with antibodies and antimicrobial peptides), that results in low efficacy of systemic immunization and weak immune response. In addition, further complications in developing natural and artificial (vaccination) immune response may be due to the high pathogen variability and low immunogenicity of related antigens. A choice of antigen is crucial upon generating any vaccine. The data on the main pathogen-derived antigens is of high importance while generating both mono- and multicomponent H. pylori vaccines. A number of various antigens was proposed for immunization against H. pylori, some of which are involved in the pathogenetic mechanisms of Helicobacter pylori infection: VacA, CagA, NapA, BabA, SabA and urease. Such vaccines turned out to be efficient in preventing experimental infection in animals. The use of purified microbial antigens successfully induces protective mechanisms to fight against infection, as demonstrated in animal studies (preventive and therapeutic protocols). Compared to using a single antigen, an association of two or three antigens can trigger stronger immune response. Currently, bacterial urease is considered as the most promising candidate antigen, which has been proved to be a valuable a vaccine antigen in numerous studies with mice, ferrets and primates. It remains unclear which route of administration for Helicobacter pylori vaccine would be superior compared to the remainder. Comparing various routes of vaccine administration demonstrated that that mice immunized intranasally and intrarectally resulted in markedly higher protection against Helicobacter pylori infection compared to oral vaccination. Development of H. pylori vaccine faced substantial obstacles due to the pathophysiological, immunological and technological challenges noted above, still remaining an issue so far. At present, a promising approach in advancing H. pylori vaccines is based on using mucosal adjuvants and generation of recombinant probiotics expressing H. pylori-derived antigens for triggering specific immune response upon vaccination.

2018 ◽  
Vol 9 (5) ◽  
pp. 829-841 ◽  
Author(s):  
V. Garcia-Castillo ◽  
H. Zelaya ◽  
A. Ilabaca ◽  
M. Espinoza-Monje ◽  
R. Komatsu ◽  
...  

Helicobacter pylori infection is associated with important gastric pathologies. An aggressive proinflammatory immune response is generated in the gastric tissue infected with H. pylori, resulting in gastritis and a series of morphological changes that increase the susceptibility to cancer development. Probiotics could present an alternative solution to prevent or decrease H. pylori infection. Among them, the use of immunomodulatory lactic acid bacteria represents a promising option to reduce the severity of chronic inflammatory-mediated tissue damage and to improve protective immunity against H. pylori. We previously isolated Lactobacillus fermentum UCO-979C from human gastric tissue and demonstrated its capacity to reduce adhesion of H. pylori to human gastric epithelial cells (AGS cells). In this work, the ability of L. fermentum UCO-979C to modulate immune response in AGS cells and PMA phorbol 12-myristate 13-acetate (PMA)-differentiated THP-1 (human monocytic leukaemia) macrophages in response to H. pylori infection was evaluated. We demonstrated that the UCO-979C strain is able to differentially modulate the cytokine response of gastric epithelial cells and macrophages after H. pylori infection. Of note, L. fermentum UCO-979C was able to significantly reduce the production of inflammatory cytokines and chemokines in AGS and THP-1 cells as well as increase the levels of immunoregulatory cytokines, indicating a remarkable anti-inflammatory effect. These findings strongly support the probiotic potential of L. fermentum UCO-979C and provide evidence of its beneficial effects against the inflammatory damage induced by H. pylori infection. Although our findings should be proven in appropriate experiments in vivo, in both H. pylori infection animal models and human trials, the results of the present work provide a scientific rationale for the use of L. fermentum UCO-979C to prevent or reduce H. pylori-induced gastric inflammation in humans.


2020 ◽  
Vol 8 (4) ◽  
pp. 479
Author(s):  
Valeria Garcia-Castillo ◽  
Guillermo Marcial ◽  
Leonardo Albarracín ◽  
Mikado Tomokiyo ◽  
Patricia Clua ◽  
...  

Lactobacillus fermentum UCO-979C (Lf979C) beneficially modulates the cytokine response of gastric epithelial cells and macrophages after Helicobacter pylori infection in vitro. Nevertheless, no in vivo studies were performed with this strain to confirm its beneficial immunomodulatory effects. This work evaluated whether Lf979C improves protection against H. pylori infection in mice by modulating the innate immune response. In addition, we evaluated whether its exopolysaccharide (EPS) was involved in its beneficial effects. Lf979C significantly reduced TNF-α, IL-8, and MCP-1 and augmented IFN-γ and IL-10 in the gastric mucosa of H. pylori-infected mice. The differential cytokine profile induced by Lf979C in H. pylori-infected mice correlated with an improved reduction in the pathogen gastric colonization and protection against inflammatory damage. The purified EPS of Lf979C reduced IL-8 and enhanced IL-10 levels in the gastric mucosa of infected mice, while no effect was observed for IFN-γ. This work demonstrates for the first time the in vivo ability of Lf979C to increase resistance against H. pylori infection by modulating the gastric innate immune response. In addition, we advanced knowledge of the mechanisms involved in the beneficial effects of Lf979C by demonstrating that its EPS is partially responsible for its immunomodulatory effect.


2020 ◽  
Vol 10 (1) ◽  
pp. 187-192
Author(s):  
O. V. Smirnova ◽  
A. A. Sinyakov

At present, the level of Helicobacter pylori infection is determined by geographic area, gender and age of the examined individuals, and can reach up to 95% of the total population. Environmental adaptation of H. pylori is exhibited in its ability to adhere to the gastric mucosal epithelium and modulated expression of its own virulent factors. Current concepts implicate that H. pylori can survive inside epithelial cells, evading host immune response. Cytokines are produced by immune cells and act to regulate its major stages. A cytokine cascade launched after Helicobacter pylori infection triggers immune reactions, progression of chronic inflammatory and destructive processes in the gastric mucosa. The role of cytokines in precancerous diseases of the stomach is ambiguous because, on the one hand, they activate immune response aimed at eliminating the pathogen, whereas on the other hand, they do contribute to the disease progression. The aim of our study was to examine profile of some cytokines and features of cytokine regulation in H. pylori-infected middle-aged males with chronic gastritis (CG) as well as chronic atrophic gastritis (CAG). In patients with CG with H. pylori, CAG and CAG with H. pylori, an increase in the cytokine IL-2 was observed that might contribute to augmented damaging effect of cytotoxic lymphocytes, as well as implementation of antitumor effect. CAG with H. pylori was featured with IL-8 hyperproduction, which resulted in increased absolute numbers of band neutrophils in peripheral blood and their decreased phagocytic activity evidencing about altered host defense mechanisms. There was increased amount of IFNy involved in recognition of malignantly transformed cells and upregulated expression of the major histocompatibility complex molecules on antigen-presenting cells. In patients with CG with H. pylori and CAG with H. pylori, production of IL-4 was increased, which might serve as a contributing factor to the chronicity of H. pylori-associated diseases. Overproduction of type 1 and type 2 cytokines indicates about activated Th1 and Th2 type immune reactions in H. pylori-associat-ed CG. A potent pro-inflammatory cytokine cascade triggers inflammatory changes in gastric mucosa with developing neutrophil infiltration and lymphocyte activation. Damage and death of epithelial cells upon inflammation form erosive and ulcerative defects, or changes manifested as gastric mucosal atrophy, metaplasia and neoplasia. The data obtained may be used as additional diagnostic criteria in early diagnostics of precancerous stomach diseases.


Author(s):  
A. Lembo ◽  
L. Caradonna ◽  
T. Magrone ◽  
M. L. Mastronardi ◽  
D. Caccavo ◽  
...  

Antibiotics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 845
Author(s):  
Candace Goodman ◽  
Katrina N. Lyon ◽  
Aitana Scotto ◽  
Cyra Smith ◽  
Thomas A. Sebrell ◽  
...  

Helicobacter pylori infection is commonly treated with a combination of antibiotics and proton pump inhibitors. However, since H. pylori is becoming increasingly resistant to standard antibiotic regimens, novel treatment strategies are needed. Previous studies have demonstrated that black and red berries may have antibacterial properties. Therefore, we analyzed the antibacterial effects of black and red raspberries and blackberries on H. pylori. Freeze-dried powders and organic extracts from black and red raspberries and blackberries were prepared, and high-performance liquid chromatography was used to measure the concentrations of anthocyanins, which are considered the major active ingredients. To monitor antibiotic effects of the berry preparations on H. pylori, a high-throughput metabolic growth assay based on the Biolog system was developed and validated with the antibiotic metronidazole. Biocompatibility was analyzed using human gastric organoids. All berry preparations tested had significant bactericidal effects in vitro, with MIC90 values ranging from 0.49 to 4.17%. Antimicrobial activity was higher for extracts than powders and appeared to be independent of the anthocyanin concentration. Importantly, human gastric epithelial cell viability was not negatively impacted by black raspberry extract applied at the concentration required for complete bacterial growth inhibition. Our data suggest that black and red raspberry and blackberry extracts may have potential applications in the treatment and prevention of H. pylori infection but differ widely in their MICs. Moreover, we demonstrate that the Biolog metabolic assay is suitable for high-throughput antimicrobial susceptibility screening of H. pylori.


2012 ◽  
Vol 80 (7) ◽  
pp. 2286-2296 ◽  
Author(s):  
William E. Sause ◽  
Andrea R. Castillo ◽  
Karen M. Ottemann

ABSTRACTThe human pathogenHelicobacter pyloriemploys a diverse collection of outer membrane proteins to colonize, persist, and drive disease within the acidic gastric environment. In this study, we sought to elucidate the function of the host-induced geneHP0289, which encodes an uncharacterized outer membrane protein. We first generated an isogenicH. pylorimutant that lacksHP0289and found that the mutant has a colonization defect in single-strain infections and is greatly outcompeted in mouse coinfection experiments with wild-typeH. pylori. Furthermore, we used protease assays and biochemical fractionation coupled with an HP0289-targeted peptide antibody to verify that the HP0289 protein resides in the outer membrane. Our previous findings showed that theHP0289promoter is upregulated in the mouse stomach, and here we demonstrate thatHP0289expression is induced under acidic conditions in an ArsRS-dependent manner. Finally, we have shown that theHP0289mutant induces greater expression of the chemokine interleukin-8 (IL-8) and the cytokine tumor necrosis factor alpha (TNF-α) in gastric carcinoma cells (AGS). Similarly, transcription of the IL-8 homolog keratinocyte-derived chemokine (KC) is elevated in murine infections with the HP0289 mutant than in murine infections with wild-typeH. pylori. On the basis of this phenotype, we renamed HP0289 ImaA forimmunomodulatoryautotransporter protein. Our work has revealed that genes inducedin vivoplay an important role inH. pyloripathogenesis. Specifically, the outer membrane protein ImaA modulates a component of the host inflammatory response, and thus may allowH. pylorito fine tune the host immune response based on ImaA expression.


2018 ◽  
Vol 7 (5) ◽  
pp. 217-224
Author(s):  
Zouaouia Chama ◽  
Khedoudj Kanoun ◽  
Fatima Zohra Elkadi ◽  
Kara Turqui Douidi ◽  
Noria Harir ◽  
...  

Helicobacter pylori infection concerns half of the world’s population, mainly in developing countries. It causes several gastrodudenal pathologies such as gastritis, ulcer and gastric adenocarcinoma. The aim of our study was to determine the prevalence of H.pylori infection and to assess the impact of different epidemiological factors as well as principal gastric diseases associ-ated to this infection. We underwent a prospective study during 18 months (month 2016-month 2017) which implicated 201 symptomatic patients for gastric fiboptic endoscopy at the level of Sidi Bel Abbes University hospital. We collected patients’ biopsies to perform a histological study and H. pylori culture. H. pylori identification was carried out based on bacteriological and biochemical analysis. The middle age of our population was (47.29 ±15.97ans) and the sex-ratio =0,8. The global prevalence of Helicobacter pylori infection is of 61.2% (123/201). This rate, after a statistic analysis, seems to be significantly related to age. It is particularly high especially for patients belonging to age range (20-30)-(51-60) years. The gender did not affect the infection prevalence that is more frequent in the gastritis case. We noticed also that HP infection prevalence was important in SBA the hospital. The range age (20-30)-(51-60) years had the highest prevalence of H. pylori and of gastritis which might be a risky ground of gastric cancer appearance. The ulcer pathology maximal rate concerned the group of 51 to 60 years. Above this age, this rate dropped whereas the number of patients suffering from gastric cancer, which presents an important rate in our study, increase for the group of 61-70 years.


mBio ◽  
2017 ◽  
Vol 8 (4) ◽  
Author(s):  
Alevtina Gall ◽  
Ryan G. Gaudet ◽  
Scott D. Gray-Owen ◽  
Nina R. Salama

ABSTRACT Helicobacter pylori is a bacterial pathogen that colonizes the human stomach, causing inflammation which, in some cases, leads to gastric ulcers and cancer. The clinical outcome of infection depends on a complex interplay of bacterial, host genetic, and environmental factors. Although H. pylori is recognized by both the innate and adaptive immune systems, this rarely results in bacterial clearance. Gastric epithelial cells are the first line of defense against H. pylori and alert the immune system to bacterial presence. Cytosolic delivery of proinflammatory bacterial factors through the cag type 4 secretion system ( cag -T4SS) has long been appreciated as the major mechanism by which gastric epithelial cells detect H. pylori . Classically attributed to the peptidoglycan sensor NOD1, recent work has highlighted the role of NOD1-independent pathways in detecting H. pylori ; however, the bacterial and host factors involved have remained unknown. Here, we show that bacterially derived heptose-1,7-bisphosphate (HBP), a metabolic precursor in lipopolysaccharide (LPS) biosynthesis, is delivered to the host cytosol through the cag -T4SS, where it activates the host tumor necrosis factor receptor-associated factor (TRAF)-interacting protein with forkhead-associated domain (TIFA)-dependent cytosolic surveillance pathway. This response, which is independent of NOD1, drives robust NF-κB-dependent inflammation within hours of infection and precedes NOD1 activation. We also found that the CagA toxin contributes to the NF-κB-driven response subsequent to TIFA and NOD1 activation. Taken together, our results indicate that the sequential activation of TIFA, NOD1, and CagA delivery drives the initial inflammatory response in gastric epithelial cells, orchestrating the subsequent recruitment of immune cells and leading to chronic gastritis. IMPORTANCE H. pylori is a globally prevalent cause of gastric and duodenal ulcers and cancer. H. pylori antibiotic resistance is rapidly increasing, and a vaccine remains elusive. The earliest immune response to H. pylori is initiated by gastric epithelial cells and sets the stage for the subsequent immunopathogenesis. This study revealed that host TIFA and H. pylori -derived HBP are critical effectors of innate immune signaling that account for much of the inflammatory response to H. pylori in gastric epithelial cells. HBP is delivered to the host cell via the cag -T4SS at a time point that precedes activation of the previously described NOD1 and CagA inflammatory pathways. Manipulation of the TIFA-driven immune response in the host and/or targeting of ADP-heptose biosynthesis enzymes in H. pylori may therefore provide novel strategies that may be therapeutically harnessed to achieve bacterial clearance.


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